British pop hunk Robbie Williams is planning a collaboration with pop superstars Abba. The former Take That star has held secret talks with ANNI-FRID LYNGSTAD, a member of the Swedish band. The 60-year-old reveals, "Robbie and I talked about doing an Abba hit together. "He has not yet come back to me on that one." Fans of the 1970s group hope Williams will reunite them, 23 years after the four-piece split. A source says, "Maybe he could be the one to get them together again. It would be a sensational coup."